Modular and morphable air vehicle

ABSTRACT

An air module may be attached to a ground module. The air module may be equipped with a center of gravity effector to change the relative locations and hence the center of gravity of the air and ground modules when the modules are attached. The center of gravity effector may be active or passive or a combination of active and passive. The center of gravity effector may be combined with a center of lift effector to change the relative locations of the center of gravity and center of lift.

I. RELATED APPLICATIONS

This continuation patent application is entitled to priority from U.S.Provisional Patent Application 61/345,535, filed May 17, 2010 by John W.Piasecki and others and from U.S. Provisional Patent Application No.61/416,965 filed Nov. 24, 2010 by John W. Piasecki and others, whichapplications are incorporated by reference in this document as if setforth in full herein. This application claims priority from U.S. utilitypatent application Ser. No. 13/068,601 filed May 16, 2011 by John W.Piasecki and others and issued as U.S. Pat. No. 9,045,226 on Jun. 2,2015, which application and patent are incorporated by reference in thisdocument as if set forth in full herein. This application claimspriority from U.S. utility application Ser. No. 14/684,995 filed Apr.13, 2015 by John W. Piasecki and others, issued as U.S. Pat. No.9,393,847 on Jul. 19, 2016. This application claims priority from U.S.utility application Ser. No. 15/205,162 filed Jul. 8, 2016 by John W.Piasecki and others, which will be issued as U.S. Pat. No. 9,610,817 onApr. 4, 2017. All of the above applications and patents are entitled“Modular and Morphable Air Vehicle.” The following documents attached toand incorporated by reference into provisional application 61/345,535are hereby incorporated by reference as if set forth in full herein:

A. PiAC Proposal No. 459-X-1, pages 3 through 26

B. PiAC Report No. 459-X-2, pages 1 through 35

C. PiAC Proposal No. 159-X-50, pages 3 through 47.

II. BACKGROUND OF THE INVENTION

A. Field of the Invention

The Invention is a modular air vehicle. The air vehicle includes anunmanned air module and a ground module that may be releasably attachedto the air module. The ground module may be a wheeled passenger vehicleand may be driven on the ground under its own power either with orwithout the air module attached. Alternatively, the ground module may bea medical module, a cargo module, a weapons module, a passenger moduleor a communications module. The air module can fly either with orwithout the ground module engaged and can support the ground module inflight in any of three different configurations. The air module andground module combination may fly as a rotary wing aircraft and also mayfly as a tilted-rotor, fixed wing aircraft. Alternatively, the airmodule may fly as an open rotor rotary wing aircraft with or withouttilted-rotor capability or may fly as an autogyro with or without jumpcapability.

B. Description of the Related Art

The prior art does not teach the modular, optionally manned, morphing,autonomous air vehicle of the invention.

III. BRIEF DESCRIPTION OF THE INVENTION

The invention is an air vehicle. The air vehicle includes an unmannedair module and any of several different ground modules, which may bemanned or unmanned. The air module may fly independently of the groundmodule. The air module and ground module may be selectably engaged tomorph the air module into an air and ground module combination. The airmodule may support the ground module in flight. The ground module maysupport the air module when the air module and attached ground moduleare on the ground. The ground module may be a vehicle ground module andmay support the attached air module on the ground, both when the vehicleground module is stationary and when the vehicle ground module is movingon the surface of the ground.

A. Ground Module

The ground module may be a vehicle ground module that is capable oftransporting adult human beings over the ground under its own power,either with or without the air module attached. Alternatively, theground module may be a cargo/payload module, a medical transport module,a weapons system platform, a passenger module, a communications moduleor may be configured to contain any other load that a user may wish totransport through the air.

The ground module and air module combination may be configured toaccommodate human beings and to transport those human beings through theair. For example, the medical module is configured to accommodate humanpatients and a human attendant. The ground vehicle module is configuredto accommodate one or more soldiers and their equipment.

B. Air Module

The air module includes at least one rotary wing. The, at least onerotary wing is configured to support the air module in flight. The atleast one rotary wing also is configured to support the ground moduleand any cargo and human passengers that are inside the ground module inflight when the ground module is attached to the air module. The airmodule includes the engine(s), rotors, drive system, avionics, sensors,communications relays and autopilot control system to allow the airmodule to fly.

The air module is autonomous and unmanned. As used in this document, theterm “autonomous” means that the air module may take-off, fly and landunder the control of an autopilot control system. As used in thisdocument, the term “unmanned” means that the air module does notaccommodate a human pilot on board the air module, although a humanoperator may program the autopilot control system prior to flight,including selection of a mission plans, waypoints and a landing zone.During flight, a human operator also may select or change the missionplan, waypoints and landing point from a remote station or from a groundmodule or may control the air module remotely.

1. Twin Ducted-Fan Air Module

The air module may use any configuration of rotary wings known in theaircraft art to support an aircraft in flight. In one embodiment, theair module features two ducted fans joined by a central unit. Eachducted fan comprises a circular duct surrounding a rotor. The centralunit houses the engine(s), drive system for the two ducted fans, starterbatteries, flight avionics, optional sensors, communications relays andautopilot control system. The air module landing gear can double as aload-carrying structure for attachment to the ground module. The tworotors in the two ducted fans are rigid in that flapping or lead and laghinges are not provided. The use of rigid rotors provides flexibility inaccommodating changes to the center of gravity of the aircraft. The airmodule featuring ducted fans is referred to herein as the “ducted fanair module.”

The twin ducted fan air module can transition among three differentconfigurations in flight (that is, ‘in stride’) while supporting theground module. In the first, or tandem rotor configuration, the twoducted fans are oriented fore-and-aft along the longitudinal axis of theground module with the axes of rotation of the two rotors in a generallyvertical direction. In the second, or side-by-side rotor configuration,the two ducted fans are located on either side of the longitudinal axisof the ground module with the axes of rotation of the two rotorsgenerally in a vertical direction. In both the tandem and side-by-siderotor configurations the air module flies as a rotary wing aircraft.

In the third, or tilted-rotor configuration, the ducted fans are locatedon either side of the ground module, as in the side-by-side rotorconfiguration, but with the axes of rotation of the two rotors orientedgenerally parallel to the longitudinal axis of the ground module. In thetilted-rotor configuration, the air module flies as a tilted-rotor,fixed-wing aircraft with the rotors serving as propellers urging theaircraft forward.

When in the tilted-rotor configuration, the two ducts for the ductedfans serve as circular wings. The forward movement of the air modulemoves air over the circular wings, providing lift to the air module. Awing extension may be attached to the outboard end of each of the ductsfor the two ducted fans. The wing extensions may be hinged to reduce thesize of the air module when the wing extensions are not providing lift.The two wing extensions provide additional wingspan and wing area andhence provide additional lift to the air module in the tilted-rotorconfiguration. The two wing extensions may be arcuate in shape and mayconform to the shape of the circular ducts for compact storage. Thecentral unit also may be of an airfoil shape. The circular wings, thewing extensions and the central unit provide lift to support the weightof the air module and the ground module in flight when the air module isin the tilted-rotor configuration and moving forward through the air.

Operation in the tandem rotor configuration provides the air module witha narrow profile and allows the aircraft to operate in confined urbansettings and even allows cargo or passengers to be loaded or unloaded toand from upper stories of buildings. The tandem rotor configurationinvolves penalties in hover performance because the downwash of theducted fans is partially obstructed by the fore and aft portions of theground module. The side-by-side rotor configuration avoids the downwashpenalty, but the larger profile presented by the vehicle restrictsoperation in confined areas. The tilted-rotor configuration provides fora higher air speed and longer range of flight than is possible in eitherthe tandem or side-by-side rotor configurations.

Each of the rotors is connected to the central unit using a torsion beamthat is flexible in torsion, which allows the rotors and ducts to tiltwith respect to each other when twisting moments are applied to thetorsion beams. The torsion beams supports the ground module when the PAVis in flight. The torsion beams also support the rotors on the groundmodule when the PAV is on the ground. The rotors have differential andnon-differential monocyclic pitch control in the direction normal to theaxis of rotor tilt of the two rotors. The rotors also have differentialand non-differential collective pitch control. The combination of thetorsion beam and monocyclic pitch control, along with collective pitchcontrol, allows control of the PAV in all axes in all threeconfigurations. The ducted fans may be equipped with exit vanes thatswivel about a vane axis parallel to the axis of rotor tilt. The vanesprovide redundant control to the monocyclic pitch control and mayprovide additional wing area and hence additional lift when the airmodule is in the tilted-rotor configuration.

Yaw control: When the air module is in the first (tandem) or second(side-by-side) rotor configuration, applying differential monocyclicpitch applies a twisting moment to the flexible torsion beam, tiltingthe rotors differentially and allowing the rotors to apply a yawingmoment to the aircraft, hence controlling yaw. In the tandem andside-by-side rotor configurations, differential vane angle control alsocontrols yaw. When the aircraft is in the third (tilted-rotor)configuration, applying differential collective pitch to the two rotorscontrols yaw.

Pitch control: When the aircraft is in the first (tandem) rotorconfiguration, applying differential collective pitch to the rotorscontrols aircraft pitch. When in the side-by-side rotor configuration orthe tilted-rotor configuration, applying non-differential monocyclicpitch to the rotors applies a pitching moment to the aircraft,controlling aircraft pitch. In the tilted-rotor configuration, vaneangle control also controls aircraft pitch. Exhaust gas from theengine(s) may be vectored to provide additional pitching moments in thetilted-rotor or tilt duct configuration.

Roll control: When the aircraft is in the first (tandem) rotorconfiguration, applying non-differential monocyclic pitch to the rotorsapplies a rolling moment to the aircraft, controlling roll. When theaircraft is in the second (side-by-side) rotor configuration, applyingdifferential collective pitch to the rotors controls roll. When theaircraft is in the third (tilted-rotor) configuration, applyingdifferential monocyclic pitch to the rotors applies a rolling moment tothe aircraft, controlling roll. Differential vane control also willcontrol roll in the tilted-rotor configuration.

During transition from the side-by-side rotor configuration totilted-rotor configuration, non-differential monocyclic pitch assiststhe rotors in tilting to the tilted-rotor configuration, allowing use ofsmaller and lighter effectors to accomplish the transition.

2. Open Rotor Air Module

The air module may dispense with circular ducts surrounding the one ormore rotors. Such an air module is hereinafter referred to as an “openrotor air module.” The open rotor air module also features a centralunit that houses the engine(s), drive system, starter batteries, flightavionics, optional sensors, communications relays and autopilot controlsystem. The central unit also can provide landing gear to support theopen rotor air module when the open rotor air module is not flying andis not in engagement with the ground module. The central unit providesan attachment location between the open rotor air module and groundmodule, allowing the air module to morph to a combination of an airmodule and a ground module. If the air module utilizes a single rotor,either an open rotor or a ducted fan, a reaction thruster is provided tocounteract the moment of the turning rotor, as in a conventional singlerotor helicopter. The reaction thruster can be a propeller, ducted fan,turbojet or any of the reaction thrusters known in the rotary wingaircraft art. If two rotors are utilized, either ducted fans or openrotors, the rotors will be counter-rotating, avoiding the need for thereaction thruster. The two counter-rotating open rotors may be coaxial,may be intermeshing, may be located in tandem and may be locatedside-by-side.

The open rotor air module may feature two open rotors connected to andpowered by the central unit. The twin open rotor air module may becapable of transitioning among the tandem rotor configuration, theside-by-side rotor configuration and the tilted-rotor configuration, asdescribed above for the twin ducted-fan air module. The twin open rotorair module does not feature ducts and hence does not feature circularwings; however, the open rotor air module may feature a tilt wing andmay feature deployable wing extensions. In all other respects, thedescriptions and figures of this application applicable to the twinducted fan air module apply equally to a twin open rotor air module.

The air module also may be configured with three or more rotors allconnected to and powered by the central unit. The three or more rotorsmay be open rotors or ducted fans.

Unless the context otherwise requires, as used in this application theterm “air module” refers to both a ducted fan fair module and an openrotor air module.

3. Autogyro Air Module

The air module may be an autogyro, which may be a ‘jump’ autogyro. Inthe jump autogyro air module, an open rotor is connected to an enginelocated in the central unit. The engine will turn the rotor to preparethe air module for takeoff. Turning the rotor temporarily stores kineticenergy in the rotor. To take off, the spinning rotor is disengaged fromthe engine and the collective pitch of the autogyro rotor blades isincreased. The kinetic energy of the spinning rotor blades is convertedto lift and the jump autogyro air module rises vertically from theground.

Either before takeoff or during the ascent, the engine is connected to apropeller or other vectored thruster that urges the jump autogyro airmodule forward. As the airborne jump autogyro air module acceleratesforward, air passes through the rotor disc from the lower side of thedisc to the upper side. Once the jump autogyro air module reaches anadequate forward speed, the air moving through the rotor disc due to theforward motion of the air module maintains the rotational speed of therotor and the air module remains airborne. The jump autogyro thereforemay take off vertically and continue to fly after takeoff. The jumpautogyro air module has a single configuration in flight.

The autogyro air module is modular and may support a ground module inflight, just as a ducted fan air module or an open rotor air module maysupport a ground module. The control and other systems of the jumpautogyro air module operate as do the equivalent systems of the ductedfan and open rotor air modules. The autogyro, ducted fan and open rotorair modules may be used interchangeably with a ground module.

4. Multiple Air Modules Carrying a Single Load

The ability of an air module to support a load in flight is limited bythe capabilities of the air module; however, two or more air modules maycooperate to transport a single load that is too large or too heavy tobe transported by a single air module. The number of air modules thatmay be attached to a load is limited only by the space physicallyavailable on the load for attachment of the air modules. For large orheavy loads, the air modules may be attached to a interconnectingstructure and the load supported by the interconnecting structure. Thetwin ducted fan or twin open rotor air modules described above may flyin any of the tandem, side-by-side or tilted-rotor configurations whentwo or more of those air modules are cooperating to transporting a largeor heavy load.

The autopilot control systems of the two or more air modules cooperateto coordinate control among all of the air modules supporting the largeor heavy load.

5. Control System

The autopilot control system of the air module is housed in the centralunit of the unmanned air module. The autopilot control system includes amicroprocessor, computer memory, data links, sensors and controleffectors. The autopilot control system allows a mission plan to bepre-programmed into the computer memory, including waypoints and landingzone location. A human operator at a remote location or in the groundmodule may change the mission plan, waypoints or landing zone locationduring flight. The autopilot control system allows the air module tooperate autonomously and independently of a ground module.

The air module control system allows the air module or the air moduleand ground module combination to transition among the first, second andthird configurations ‘in stride.’ As used in this document, the term ‘instride’ means that the air module may transition among the tandem rotorconfiguration, the side-by-side rotor configuration and the tilted-rotorconfiguration starting during hover or low speed flight or duringon-road travel by the air module and ground module combination. Whiletraveling on the ground, the air module and ground module combinationmay transition to the third (tilted-rotor) configuration, take off, flyand land as a short takeoff and landing (STOL) aircraft.

The air module can be configured to fly autonomously, including flyingautonomously to a safe location after disengaging with the groundmodule, flying to and re-engaging with the ground module when needed,autonomously engaging with and transporting cargo containers, andautonomously engaging and transporting medical transportation units,such as to evacuate a wounded soldier from a battlefield. The air modulealso may operate under manual human control, in a fly-by-wireconfiguration or by remote control.

6. Active Center-of-Gravity Control

The air module or ground module may be equipped with active center ofgravity (CG) control. The CG control detects changes in the center ofgravity of the airborne aircraft, such as by soldiers and equipmentembarking and disembarking from the ground module while the aircraft isin hover, and adjusts the CG accordingly to maintain the commandedattitude of the aircraft. Attitude sensors detect the attitude of theaircraft and supply the attitude information to the microprocessor. Themicroprocessor compares the detected attitude to the commanded attitudeof the aircraft. If there is a discrepancy, the microprocessor activatesactuators and adjusts the relative position of the center of lift andthe center of gravity to restore the commanded attitude.

Center of gravity adjustment may involve moving the center of gravitywith respect to the center of lift by moving the ground module withrespect to the air module so that the center of gravity of the aircraft,its load and it occupants is directly below the center of lift of therotor(s) and wing when the aircraft is flying at the commanded attitude.

Alternatively, active CG control may take the form of moving the centerof lift of the air module with respect to the ground module. Forexample, differential collective pitch applied to the rotors of the tworotor embodiment having three configurations will adjust the center oflift along the rotor axis of tilt. For the open rotor air module andgyrocopter air module, active CG control may involve moving the rotorwith respect to the air module, as by tilting the rotor pylon ortraversing the rotor attach point. Lateral CG errors are as well managedby the use of a mechanical motion to displace the center of lift to meetthe line of action imparted by the lift system directly thru the centerof gravity.

Active CG control also can raise or lower the ground module with respectto the air module, allowing CG control in three dimensions.

Active CG control may include both moving the center of gravity andmoving the center of lift.

7. Rotor Configuration

The air module may be equipped to change the configuration of the rotor,particularly of open rotor or autogyro air modules for takeoff andlanding. The rotor mast of an open rotor or autogyro air module may beextended to provide additional ground clearance to avoid injury topersons near the air module and damage to the rotors during takeoff orlanding.

The rotor blades of the open rotor or autogyro air module may betelescoping or otherwise extendable to allow changes in diameter of therotor disc. The use of extendable rotor blades allows the air module tobe transportable over the road, as when the air module is supported bythe operating ground vehicle module, with the rotor blades in thecontracted or non-extended position. When the rotor disc is in thecontracted or non-extended position, the rotor presents a smaller crosssection and allows the air module to avoid obstacles on the ground. Byextending the blades, the area of the rotor disc is increased, allowingbetter vertical flight performance than could otherwise be achieved withthe smaller radius of the retracted system.

The rotor blades of the open rotor air module or the autogyro air modulemay be foldable, as is known in the art, so that the air module presentsa smaller cross section while traveling on the ground and to avoidobstacles on the ground.

In an example application of the invention, a twin ducted fan air moduleis attached to vehicle ground module. The air module is unmanned and isprogrammed to transports soldiers occupying the ground vehicle module ona mission. The air module takes off in the side-by-side configurationand the air module autopilot follows a pre-determined mission plan to apre-selected location along pre-selected way points. For higher speedand longer range, the air module transitions to the tilted-rotorconfiguration during flight. The soldiers alter the mission plan inflight by selecting an alternative landing point in an urban area. Theair module transitions to the tandem rotor configuration during flightand the air module and ground module combination lands at the selectedurban landing zone. The air module and ground module disengage and theair module takes off. The soldiers in the ground module drive the groundvehicle module over the ground to the objective. The air module may flyoverhead and communicate with the soldiers in the ground vehicle moduleto provide surveillance or airborne weapons support or may fly to apredetermined safe landing zone and await instructions. Upon command,the air module flies to the location of the ground module, reattaches tothe ground module and transports the vehicle ground module and thesoldiers back to base.

IV. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective schematic drawing of the twin rotor, threeconfiguration embodiment in the tandem rotor configuration.

FIG. 2 is a perspective schematic drawing of the twin rotor, threeconfiguration embodiment in the side-by-side rotor configuration.

FIG. 3 is a perspective schematic drawing of the twin rotor, threeconfiguration embodiment in the tilted-rotor configuration.

FIG. 4 is a perspective view of the twin rotor ducted air module inrotary wing flight without a ground module attached.

FIG. 5 is a perspective view of the twin rotor ducted fan air module inthe tilted-rotor configuration.

FIG. 6 is a perspective view of the twin rotor, three configuration airmodule in the tilted-rotor configuration with a vehicle ground moduleattached.

FIG. 7 is a front view of the twin rotor, three configuration air modulewith a vehicle ground module attached and on the ground.

FIG. 8 is a perspective view of the twin rotor, three configuration airmodule in the tilted-rotor configuration with a different ground moduleattached.

FIG. 9 is a perspective view of the open rotor twin rotor air module inthe tandem rotor configuration with a vehicle ground module attached.

FIG. 10 is a perspective view of the open rotor twin rotor air module inthe side-by-side rotor configuration with the vehicle ground moduleattached.

FIG. 11 is a perspective view of the open rotor twin rotor air module inthe tilted-rotor configuration with the vehicle ground module attached.

FIG. 12 is a detail cross section view of a ducted fan.

FIG. 13 is a perspective schematic view of the twin rotor air module andground module combination having a torsion beam and monocyclic pitch inthe side-by-side rotor configuration.

FIG. 14 is a perspective schematic view of the twin rotor air module andground module combination having a torsion beam and monocyclic pitch inthe tilted-rotor configuration.

FIG. 15 is a plan view of a two air module embodiment in theside-by-side rotor configuration.

FIG. 16 is a side view of a two air module embodiment in the tandemrotor configuration.

FIG. 17 is a plan view of the two air module embodiment in the tandemrotor configuration.

FIG. 18 is a perspective view of the two air module embodiment andground module combination in the tilted-rotor configuration.

FIG. 19 is a perspective view of the two air module embodiment andscaffold combination in the tilted-rotor configuration.

FIG. 20 is a schematic diagram of active CG control.

FIG. 21 is a detail view of a passive center of gravity (CG) control.

FIG. 22 is a detail view of an active CG control in one dimension.

FIG. 23 is a detail view of a combination of active and passive CGcontrol.

FIG. 24 is a detail view of active CG control in three dimensions.

FIG. 25 is a plan view of the active CG control of FIG. 25.

FIG. 26 is a detail view of active CG control in three dimensions.

FIG. 27 is a perspective view of the aircraft with a parachute.

FIG. 28 is a schematic of an inflatable bag.

FIG. 29 is a schematic diagram of the control system.

FIG. 30 is a schematic diagram of the control system.

FIG. 31 is a schematic diagram of the control system.

FIG. 32 is a perspective view of a single open rotor embodiment.

FIG. 33 is a perspective view of a coaxial open rotor embodiment.

FIG. 34 is a perspective view of an autogyro air module and groundmodule combination.

FIG. 35 is a partial cutaway view of a tilting, extendable mast for anautogryo air module.

FIG. 36 is a detail of a tilting mast for an open rotor air module.

FIG. 37 is a detail cross section of an extendable mast for a open rotorair module, with the mast in the retracted position.

FIG. 38 is a detail cross section of an extendable mast for an openrotor air module with the mast in the extended position.

FIG. 39 is a perspective view of an extendable rotor in the retractedposition.

FIG. 40 is a perspective view of an extendable rotor in the extendedposition.

FIG. 41 is a cutaway view of the extendable rotor in the retractedposition.

FIG. 42 is a cutaway view of the extendable rotor in the extendedposition.

V. DESCRIPTION OF AN EMBODIMENT

The invention is an air vehicle having at least one rotary wing 4. Theair vehicle may be modular and may transition between differentconfigurations while still providing transportation function.

A. Two Rotor Embodiment having Three Configurations

FIGS. 1, 2 and 3 illustrate the elements for a twin rotor air vehiclethat can transition between three different configurations. The twinrotor embodiment includes a fuselage 3 and a first rotor 14 and a secondrotor 16. The first rotor 14 and the second rotor 16 are configured tosupport the fuselage 3 in flight. The twin rotor air vehicle may bemodular, in which case the first and second rotors 14, 16 along with thedrive and control system for the rotors 14, 16 define an air module 2and the fuselage 3 defines a ground module 6, as shown by FIGS. 4through 8 and discussed below. The air module 2 and the ground module 6may be selectably detached.

The fuselage 3 defines a longitudinal axis 8 in a fore and aft direction10, 12 and generally oriented along a preferred direction of flight forthe fuselage 3.

The first rotor 14 has a first rotor axis of rotation 24 and the secondrotor 16 has a second rotor axis of rotation 26, about which the firstand second rotors 14, 16 are configured to rotate. The first and secondrotor axes of rotation 24, 26 are in a spaced-apart relation along anaxis of rotor tilt 20. The first and second rotor axes of rotation 24,26 generally are parallel and together generally define a plane.

The axis of rotor tilt 20 may rotate selectably about a translation axis28 between the tandem position 22 shown by FIG. 1, in which the axis ofrotor tilt 20 is parallel to the longitudinal axis 8, and theside-by-side position 30 shown by FIG. 2 in which the axis of rotor tilt20 is generally normal to the longitudinal axis 8. When the first andsecond rotor axes of rotation 14, 16 are in the side-by-side position30, the plane generally defined by the first and second rotor axes ofrotation 14, 16 is generally normal to the longitudinal axis 8. Thefirst and second rotor axes of rotation 14, 16 are configured to moveselectably between a vertical position 34, shown by FIGS. 1 and 2, and ahorizontal position 36, shown by FIG. 3.

The first and second rotors 14, 16 are configured to move between threedifferent flight configurations. The first flight configuration is thetandem rotor configuration 18 shown by FIG. 1. When the axis of rotortilt 20 is in the tandem position 22 and the rotor axes of rotation arein the vertical position 34, the first and second rotors 14, 16 are inthe tandem rotor configuration 18. In the tandem rotor configuration 18,the first and second axes of rotation 24, 26 are generally normal to andgenerally intersect the longitudinal axis 8 and the longitudinal axis 8generally falls on the plane defined by the first and second rotor axesof rotation 8. The air vehicle can fly in the tandem rotor configuration18 as a rotary wing aircraft.

The second flight configuration is the side-by-side rotor configuration32 shown by FIG. 2. From FIG. 2, the air module 2 is in a side-by-siderotor configuration 32 when the axis of rotor tilt 20 is in theside-by-side position 30 and the first and second axes of rotation 24,26 of the first and second rotors 14, 16 are oriented in a verticalposition 34. When the air vehicle is in the side-by-side rotorconfiguration 32, the plane defined by the first and second axes ofrotation 24, 26 of the first and second rotors 14, 16 is generallynormal to the longitudinal axis 8. The air vehicle can fly as a rotarywing aircraft when the air module 2 is in the side-by-side rotorconfiguration 32 and when the air module 2 is translating between thetandem rotor configuration 18 and the side-by-side rotor configuration32.

The third flight configuration is the tilted-rotor configuration 38shown by FIG. 3. The air vehicle is in the tilted-rotor configuration 38when the axis of rotor tilt 20 is in the side-by-side position 30 andthe first and second rotor axes of rotation 24, 16 are in the horizontalposition 36, all as shown by FIG. 3. When the first and second rotors14, 16 are in the tilted-rotor configuration 38, the plane defined bythe first and second axes of rotation 24, 26 is generally parallel tothe longitudinal axis 8.

In the tilted-rotor configuration 38, the air module 2 flies as afixed-wing aircraft with the rotors 14, 16 acting as propellers urgingthe air module 2 through the air. To fly as a fixed-wing aircraft, theair module 2 must have a wing 40, as described below relating to FIGS.5, 6, 8, and 9 through 11.

B. Modular Two Rotor Ducted Fan Embodiment

FIGS. 4 through 8 illustrate a twin rotor ducted fan embodiment of theair module 2. As shown by FIGS. 4 through 8, first rotor 14 may besurrounded by a first circular duct 42 and second rotor 16 may besurrounded by a second circular duct 44 to form a first ducted fan 46and a second ducted fan 48. The use of ducted fans 46, 48 allows thefirst rotor 14 and second rotor 16 to generate more thrust for a givenrotor 14, 16 diameter than otherwise would be possible. The first andsecond circular ducts 42, 44 also serve to protect rotors 14, 16 fromdamage.

In each embodiment and all configurations, a central unit 50 houses theengine(s) to power the rotors 14, 16. The central unit 50 houses theengine(s), drive system for the two ducted fans 46, 48, starterbatteries, flight avionics, optional sensors, communications relays andautopilot control system.

In the tilted-rotor configuration 38 illustrated by FIGS. 5, 6 and 8,the first circular duct 46 acts as a first circular wing 52 and thesecond circular duct 48 acts as a second circular wing 54. Circularwings 52 and 54 provide lift to the air module 2 to support the airmodule 2 in the air when the air module 2 is in the tilted-rotorconfiguration 38 and is moving in the direction of the longitudinal axis8.

As shown by FIGS. 5, 6, and 8, a first wing extension 56 may be attachedto an outside 58 of the first circular duct 42 and a second wingextension 60 may be attached to an outside 62 of the second circularduct 44. The first and second wing extensions 56, 60 provide additionallift to support the air module 2 in the air when the air module 2 is inthe tilted-rotor configuration 38. The first and second wing extensions56, 60 may fold about a hinge 64 between a deployed position (shown byFIGS. 5, 6 and 8) and a retracted position (shown by FIG. 7) to reducethe size of the air module 2 when the first and second wing extensions56, 60 are not in use. The first and second wing extensions 56, 60 maybe arcuate in shape and may conform to the periphery 66 of the circularducts 42, 44 for compact size in the retracted position.

FIGS. 4 through 8 also illustrate the modular nature of the air vehicle.FIGS. 4 and 5 illustrate an air module 2 in flight without a groundmodule 6 attached. In FIG. 4, the air module 2 is flying as a rotarywing aircraft. The air module 2 is supported by lift generated by thefirst and second rotors 14, 16 acting as rotary wings 4.

FIG. 5 illustrates the air module 2 flying in the tilted-rotorconfiguration 38 without a ground module 6 attached, with wings 40providing lift to support the air module 2. First and second rotors 14,16 act as propellers to urge the air module 2 through the air.

FIGS. 6 and 8 illustrate the air module 2 flying in the tilted-rotorconfiguration 38 with a ground module 6 attached, with the circularwings 52,54 and wing extensions 56, 60 providing lift to support the airmodule 2 and ground module 6. The air module 2 also may support theground module 6 in flight in the tandem rotor configuration 18 and theside-by-side rotor configuration 32, with the first and second rotors14, 16 acting as rotary wings 4 to provide the required lift.

FIG. 7 illustrates the air module 2 attached to a ground module 6 in thetandem rotor configuration 18 while on the ground 74, with the groundmodule 6 supporting the air module 2 above the ground 74.

C. Two Open Rotor Embodiment

An open rotor 66 embodiment of the air module 2 having two rotors 14, 16and three rotor configurations is illustrated by FIGS. 9 through 11. Theopen rotor 66 embodiment dispenses with the circular ducts 42, 44 of theducted fan 46, 48 embodiment. The first and second rotors 14, 16 maymove through the same three rotor configurations 18, 32, 38 as theducted fan 46, 48 embodiment of FIGS. 4 through 8. FIG. 9 illustratesthe open rotor 66 air module 2 in the tandem rotor configuration 18.FIG. 10 illustrates the open rotor air module 2 in the side-by-siderotor configuration 32. FIG. 11 illustrates the open rotor air module 2in the tilted-rotor configuration 38. The open rotor 66 embodimentoperates in the same manner as the twin ducted fan embodiment discussedabove, except as follows.

The open rotor 66 embodiment does not feature circular ducts 44, 46 andhence does not have circular wings 52, 54. Instead, the open rotor 66embodiment has a tilt wing 68 with a chord oriented generally parallelto the first and second rotor axes of rotation 24, 26. When the airmodule 2 is flying in the tandem rotor configuration 18 shown by FIG. 9or the side-by-side rotor configuration 42 shown by FIG. 10, thevertical orientation of the chord of the tilt wing 68 reduces downwasheffects from the rotors 14, 16 against tilt wing 68. When the air module2 is transitioning to the tilted-rotor configuration 38 illustrated byFIG. 11, the tilt wing 68 tilts about the axis of rotor tilt 20 so thatthe chord of the tilt wing 68 is parallel to the longitudinal axis 8. Inthe tilted-rotor configuration 38, the tilt wing 68 provides lift tosupport the air module 2 and the ground module 6 in the air.

The tilt wing 68 may be provided with a first wing extension 56 and asecond wing extension 60. The first and second wing extension 56, 60 mayfold about hinge 64 to the retracted position to reduce the size of theair module 2 when the wing extensions 56, 60 are not in use, asillustrated by FIGS. 9 and 10. The wing extensions 56, 60 may beextended to the deployed position, illustrated by FIG. 11, extending thespan and wing area of tilt wing 68 to provide additional lift to the airmodule 2 when the air module 2 is in the tilted-rotor configuration 38.

Rotors 14, 16 for both the twin open rotor 66 embodiment and the twinducted fan embodiment may be tilted to either side of vertical when therotors 14, 16 are in the tandem rotor position 18 and the side-by-siderotor configuration 32 to provide active center of gravity (CG) control.In this configuration, the tilt of the rotors is the CG actuatorillustrated by FIG. 21.

The open rotor air module 2 may dispense with the tilt wing 68, andhence with the tilted-rotor configuration 18, in which case the airmodule 2 may fly as a rotary wing aircraft in only the tandem rotorconfiguration 18 or the side-by-side rotor configuration 32. The airmodule 2 having two open rotors 68 also may operate in positionsintermediate to the tandem rotor and side-by-side rotor configurations18, 32.

D. Ground Module

The air module 2, whether ducted fan or open rotor, may support anattached ground module 6 in flight. When the ground and air modules 6, 2are attached and on the ground 74, the ground module 6 may support theair module 2, as shown by FIG. 8. A ground module 6 may include a crewcabin 76 and be configured to accommodate one or more human beings. Forground modules 6 that are so configured, the unmanned air module 2 willsupport the attached ground module 6 and its human occupants in flight.

The ground module 6 may be a vehicle ground module 70, as illustrated byFIGS. 6, 7 and 8 through 11. The vehicle ground module 70 is configuredto move under its own power across the surface of the ground 74 eitherwith the air module 2 attached or separately from the air module 2. Thevehicle ground module 70 is configured to contain one or more humanbeings, such as one or more soldiers, and their equipment in a crewcabin 76 while it moves across the ground 74. The vehicle ground module70 includes wheels 72 that support the vehicle ground module 70 on thesurface of the ground 74. The vehicle ground module 70 include one ormore motors, such as one or more electric motors, to turn one or more ofthe wheels 72 and also includes batteries to power the motors. Thevehicle ground module 70 may move across the ground under battery poweralone. The vehicle ground module 70 may include an internal combustionengine and associated electrical generating system to extend the rangeof the vehicle ground module 70. Alternatively, a conventional internalcombustion engine may drive one or more wheels 72 directly through aconventional transmission or transaxle. Any conventional system known inthe automotive art to drive one or more wheels 72 of the vehicle groundmodule 70 is contemplated by the invention.

The vehicle ground module 6 shares a separable fuel system with the airmodule 2 and the fuel stored on either the air module 2 or the vehicleground module 70 may be used to supply the other. The vehicle groundmodule 70 also shares a separable electrical system with the air module2 and the air module turbine engine(s) 90 can supply supplementalelectrical power to the vehicle ground module wheels 74. The air module2 electrical power can be used to provide directional control to theground module 6 by applying differential power to the ground module 6wheels, resulting in skid steering.

When the vehicle ground module 70 and air module 2 are engaged, theelectrical power systems of the two modules 70, 2 are joined. Electricalpower generated by the engines 90 of the air module 2 may be used tocharge batteries of the vehicle ground module 70, drive the wheels 74 ofthe vehicle ground module or start the engine of the vehicle groundmodule 70. Conversely, the batteries or engine of the vehicle groundmodule 70 may power the starting of the engines 90 of the air module 2.

From FIG. 8, the ground module 6 may be a medical module 20 and may beconfigured to contain one or more human patients, such as woundedsoldiers on a battlefield, and one or more human attendants. The medicalmodule 20 may be equipped with systems to treat and sustain the one ormore patients until the air module 2 delivers the medical module 20 andthe patients to a care facility.

Also from FIG. 8, the ground module 6 may be a cargo module 22configured to transport any desired cargo through the air. The groundmodule 22 may be a weapons module 24 configured so that the air module 2and weapons module 24 in combination provide a remotely operated aerialweapon. The weapons module 24 may include conventional communicationsand targeting systems to allow a remote operator, such as a soldier in avehicle ground module 20, to select a target on the ground 74 and todestroy the target using the air module 2 and weapons module 24combination. The weapons module 24 may include a supplemental fuelsupply to allow the air module 2 and weapons module 24 combination anextended loiter time over a target area. The ground module may be apassenger module configured to carry human passengers or may be acommunications module equipped to accommodate communications systems.

E. Two Rotor Embodiment having Monocyclic Pitch and Torsion Beams

The two rotor embodiments capable of transition among the tandem rotorconfiguration 18, the side-by-side rotor configuration 32 and thetilted-rotor configuration 38 must provide control in the yaw, pitch androll axes for all three configurations 18, 32, 38. Control in all threeaxes in all three configurations is achieved by providing the first andsecond rotor 14, 16 with monocyclic pitch in a direction normal to theaxis or rotor tilt 20 and by mounting the rotors 14, 16 on flexibletorsion beams 86, 88, all as shown by FIGS. 12 through 14.

FIG. 12 illustrates how pitch control is applied to a blade 94 of arotor 14, 16. FIG. 12 shows a ducted fan embodiment, but the explanationapplies equally to open rotor embodiments. First rotor 14 features afirst circular duct 42 and a rotor blade 94. Rotor blade 94 is attachedto a hub 96 with a pivoting blade mount and rotates about the firstrotor axis of rotation 24. The pitch of blade 94 can vary as the bladerotates about the hub 96. Blade 94 pitch is determined by a firstswashplate 98 that rotates with the blade 94. The swashplate 98 iscapable of being tilted at a swashplate angle 104 as it rotates. A pitchlink 100 between the swash plate 98 and the blade 94 translates thechanging angle 104 of the swashplate 98 as it rotates into a changingpitch of the rotating blade 94. For monocyclic pitch control, twocontrol input pushrods 102 determine the swashplate angle 104 so thatthe change in blade 94 pitch caused by the swashplate angle 104 isgreatest when the blade 94 is farthest away from the axis of rotor tilt20 during the rotation of the blade 94 and the change in blade 94 pitchcaused by the swashplate angle 104 is substantially zero when the blade94 is parallel to the axis of rotor tilt 20. For monocyclic pitchcontrol, the change in blade 94 pitch caused by the swashplate 98 tiltapplies a torque to the hub 96 and hence to the rotor 14, 16 parallel tothe axis of rotor tilt 20.

The hub 96 is attached to the central unit 50 of the air module 2 by thefirst flexible torsion beam 86. The torque applied to the hub 96 appliesa pre-determined torsion load to the first flexible torsion beam 86,which has a pre-determined resilience in torsion, causing apre-determined angular deformation of the first flexible torsion beam86. The angular deformation of the first flexible torsion beam 86 causesa pre-determined change in the angle of tilt of the rotor axis ofrotation 24, 26 about the rotor tilt axis 20. The change in the tilt ofthe rotor axis of rotation 24, 26 changes the direction of thrust of therotor 14, applying a predetermined yaw or roll moment to the aircraft.

The second rotor 16 has a second swashplate 110 that determines a secondmonocyclic pitch of the second rotor 16. The second rotor 16 operates inthe same manner as the first rotor 14. The monocyclic pitch of thesecond rotor 16 applies a predetermined second torsion load to thesecond flexible torsion beam 88, causing a predetermined angulardeformation of the second flexible torsion beam 88 and a pre-determinedchange in the direction of thrust of the rotor 16. The first and secondrotors 14, 16 cooperate to apply a predetermined yaw or rolling momentto the aircraft.

FIGS. 13 and 14 illustrate the application of the effects describedabove relating to FIG. 12. As described above, rotors 14, 16 are rigid,meaning that the rotor blades do not flap, lead or lag. FIG. 13 showsthe ground module 6 and air module 2 in the side-by-side rotorconfiguration 32. Ground module 6 is attached to air module 2. Engines90 generate power that is transmitted to rotors 14, 16. Rotors 14, 16and ground module 6 are supported with respect to each other by flexibletorsion beams 86, 88, which are resiliently flexible in torsion. Whendifferential monocyclic pitch is applied to rotors 14, 16, the rotors14, 16 apply torsion to the torsion beams 88. Torsion of the torsionbeams 86, 88 allows the rotors 14, 16 and circular ducts 42, 44 todeflect differentially, so that the first and second rotor axes ofrotation 24, 26 move within a degree of freedom shown by arrows 106. Thedeflection of the torsion beams 86, 88 tilts the rotors 14, 16 inopposite directions, applying a yawing moment to the air module 2 andground module 6 combination, controlling yaw.

When non-differential cyclic pitch is applied to both rotors 14, 16, thetorque applied to the torsion beams 86, 88 assists in moving the rotors14, 16 from the side-by-side configuration 32 to the tilted-rotorconfiguration 38, allowing smaller and lighter control effectors to beused for that task

FIG. 14 shows the ground module 6 and air module 2 in the tilted-rotorconfiguration 38. Differential monocyclic pitch applied to rotors 2applies torsion to flexible torsion beams 86, 88, which allow the rotors14, 16 to tilt in the direction indicated by arrows 108. Thedifferential tilt of the rotors 2 applies a rolling moment to the groundmodule 6 and air module 2 combination, controlling roll.

F. Two or more Air Modules Acting in Cooperation

Two or more air modules 2 may be joined together to lift and transportloads, that are too heavy or too large for a single air module 2, asillustrated by FIGS. 15 through 19.

Two or more air modules 2 may be attached to a single ground module 6 sothat the ground module 6 becomes the physical connection between the airmodules 2. The air modules 2 may fly independently to the ground module6, join to the ground module 6, and lift the ground module 6 as a singleaircraft comprising the two air modules 2 and the ground module 6. Intwo or more air module 2 configurations, the control systems of the airmodules 2 are operably joined so that the two or more air modules 2operate as a single aircraft when supporting the ground module 6.

FIGS. 15 through 18 illustrate a two-air module 2 embodiment in whichtwo air modules 2 are attached to a single ground module 6 and theground module 6 provides the physical connection between the air modules2. FIGS. 15 and 17 are plan views of a two-air modules 2 embodiment.FIG. 16 is a side view of the two-air modules 2 embodiment and FIG. 18is a perspective view. In FIG. 15, the air modules 2 are in the second,or side-by-side configuration.

In FIGS. 16 and 17, the air modules 2 are in the tandem rotorconfiguration 18. In FIG. 18, the air modules 2 are in the tilted-rotorconfiguration 38. Air modules 2 may move between the tandem rotorconfiguration 18, the side-by-side rotor configuration 32 and thetilted-rotor configuration 38 for the two or more air modules 2configuration, just as a single air module 2 aircraft may move betweenconfigurations. FIGS. 15-19 illustrate the ducted rotors 14, 16, engines90, wing 40, wing extensions 56, 60, and flexible torsion beams 86, 88,and central units 50.

As shown by FIG. 19, two or more air modules 2 may be joined by ascaffold 108, such as a spar or frame, and the load to be lifted may berigged to the scaffold 108. When joined by a scaffold 108, the airmodules 2 may fly to the load to be lifted as a single aircraft. Asshown by FIG. 19, the two air modules 2 joined by the scaffold 108 fliesautonomously as a single aircraft, with the two air modules 2 acting incooperation.

The embodiments illustrated by FIGS. 18 and 19 provide that the two ormore air modules 2 are in close proximity and that the first (tandem)rotor configuration 18 is not possible due to interference between therotors 14, 16. In such an embodiment, the air modules 2 may beconfigured so that the air modules 2 transition only between theside-by-side rotor configuration 32 and the tilted-rotor configuration38. The air modules 2 may be configured so that the two or more airmodules 2 operate only in the side by side rotor configuration 32 whenlifting of a very heavy load is desired. In such a configuration, thelifting capacity is modular. If two air module 2 will not be adequate tosupport the load, then a third can be added. The number of air modules 2that can be applied to a load is limited only by the dimensions of thescaffold 108 or the ground module 6.

G. Dynamic Center of Gravity Control.

FIGS. 20 through 26 address dynamic center of gravity control. The pilotof a conventional aircraft must be aware of the center of gravity (‘CG’)of the aircraft to preserve the flight characteristics of the aircraft.If the CG of an aircraft moves, such as by loading or distribution ofpassengers, fuel or cargo within the aircraft, then changes in theaircraft attitude will occur that must be corrected by the pilot orcontrol system. The air module 2 and ground module 6 combination may beequipped with dynamic CG control in one, two or three dimensions toallow the aircraft to automatically respond to changes in CG duringflight.

The control system for active dynamic CG control is illustrated by FIG.20. The active dynamic CG control comprises one or more sensors 112 todetect a change or rate of change of attitude of the aircraft and todetect a deviation from the commanded attitude. The CG sensors 112 areconfigured to determine the deviation of the CG from an optimum CGlocation or envelope, which may be defined in one, two or threedimensions. The automatic control system generates a CG correctionsignal 114 to command corrections in the CG, and actuators 116 to adjustthe relative locations of the CG and the center of lift of the aircraftwhen the aircraft is in flight.

To align the center of gravity with the center of lift, the dynamic CGcontrol system 114 may move the center of gravity of the ground module 6and air module 2 combination, may move the center of lift of the airmodule, or may move both.

FIGS. 21 through 26 illustrate different embodiments that move thecenter of gravity of the ground module 6 with respect to the center oflift of the air module 2 to achieve dynamic CG control.

The CG control may be active or passive. FIG. 21 illustrates passive CGcontrol. Passive CG control may be as simple as hanging the groundmodule 6 from the air module 2 by a link 116 that is free to move in oneor two dimensions. Damping may be provided to a passive dynamic CGcontrol system to prevent unwanted oscillations. Two ball joints 118connect the link to the air module 2 and the ground module 6 for passiveCG control in two dimensions. As the center of gravity of the groundmodule 6 changes, the link 116 moves within sockets 120, automaticallycompensating for the change in CG without intervention from the controlsystem.

Because of the two spaced-apart rotors, the air module and the airmodule/ground module combination has a great deal of control power alongthe rotor axes of rotation 24, 26; that is, in roll when the aircraft isin the side-by-side rotor configuration 32 and in pitch when theaircraft is in the tandem rotor configuration 18. The air module 2 andground module 6 combination has relatively low control power in thedirection normal to the rotor axes of rotation 24, 26; that is, in pitchwhen the aircraft is in the side-by-side rotor configuration 38 and inroll when the aircraft is in the tandem rotor configuration 18. DynamicCG control therefore is most important in the dimension normal to therotor axes of rotation 24, 26.

FIG. 22 illustrates an active dynamic CG control one dimension. A pinnedlink 122 connects the air module 2 and the ground module 6. The pinnedlink 122 is capable of movement in one dimension only. A screw jack orhydraulic jack 124 receives a CG correction signal from the CG controlsystem 114 and moves the pinned link 122 to a location determined by theCG control system 114, controlling CG in one dimension.

FIG. 23 illustrates a combination active and passive dynamic CG controlin three dimensions. A flexible fabric strap 126, such as Kevlar®, isattached to the ground module 6. The other end of strap 126 is supportedby actuator 128. Actuator 128 is a screw or hydraulic jack and ismovable in the vertical direction; that is, in the direction parallel tothe axes of rotation of rotors 14, 16 when the rotors are in thevertical position 34. Actuator 128 therefore can move strap 126 in thevertical direction. Strap 126 swings freely below air module 2 andtherefore automatically adjusts CG of the aircraft in two dimensions. CGcontrol is active in the third dimension.

FIGS. 24 and 25 illustrate an active dynamic CG control in threedimensions. FIG. 24 is a detail side view. FIG. 25 is a detail cutawaytop view. First crank 130 is rotatably attached to ground module 6 andis movable in the direction indicated by arrow 131. The location offirst crank 130 is adjusted by first actuator 133. A second crank 132 isrotatably attached to first crank 130 and is movable in the directionindicated by arrow 134. Second crank 132 also is rotatably attached tovertical shaft 136. The location of second crank 132 is adjusted withrespect to first crank 130 by second actuator 135. CG therefore isadjustable in two dimensions by the operation of first and secondactuators 130, 132. Vertical shaft 136 is adjustable in the verticaldimension, indicated by arrow 138, by the operation of third actuator140, thereby adjusting CG in the third dimension. First, second andthird actuators 130, 132, 140 may be screw jacks or hydraulic cylinders.

Active dynamic CG in three dimensions also is illustrated by FIG. 26.First cross slide 142 engages ground module 6 when the air and groundmodules 2, 6 are in engagement. First cross slide 142 engages secondcross slide 144 so that first cross slide 142 is constrained to move inthe direction indicated by arrow 143 of FIG. 27 with respect to secondcross slide 144. First actuator 145 moves first cross slide 142 withrespect to second cross slide 144. Second cross slide 144 also engagescross slide base 146 so that second cross slide 144 is constrained tomove in the direction indicated by arrow 147 with respect to cross slidebase 146. Second actuator 148 moves second cross slide 144 with respectto cross slide base 146. Cross slide base 146 is attached to column 150.Column 150 constrains the motion of cross slide base 146, and henceground module 6, with respect to air module 2. Third actuator 151 movescross slide base 146 in the vertical direction indicated by arrow 152with respect to air module 2. Ground module 6 therefore is movable inthree dimensions with respect to air module 2.

The active dynamic CG control can used to assist in the directionalcontrol of the aircraft, such as for lateral translation. The rotors 14,16 do not have full cyclic pitch and have limited control power normalto the axis of rotor tilt 20 of the air module 2. The active dynamic CGcontrol may be used to tilt the aircraft and hence to move the aircraftin the direction normal to the axis of rotor tilt 20. Dynamic CG controlalso may be used to assist in dynamic flight operations, such asattitude control to assist the aircraft in turning or in slowing theforward motion of the aircraft. In this mode, active CG controlfunctions in a manner similar to weight-shift control systems employedby hang gliders, but without operator awareness or intervention as isrequired by hang gliders.

Changes to the center of gravity of the aircraft may be coupled withchanges to the center of lift. Active CG control provides redundantcontrol to collective pitch control, cyclic pitch control, rotor tiltand exit vane 154 control to control the attitude and flight of theaircraft.

H. Ducted Fan Embodiment Equipped with Exit Vanes

As shown by FIG. 7, the air module 2 may be equipped with one or moremovable exit vanes 154 oriented parallel to the axis of rotor tilt 20.First exit vane 154 is located on the downstream side of the firstducted fan 46 in the exhaust of first ducted fan 46. The second exitvane 154 is located on the downstream side of the second ducted fan 48and is located in the exhaust of the second ducted fan 48. First andsecond exit vanes 154 each may tilt about a longitudinal axis, which isoriented parallel to the axis of rotor tilt 20, to define an exit vaneangle. The exhaust air from the ducted fans 46, 48 blows across the exitvanes 154, creating a reaction force on each vane 154 that is adjustableby adjusting the exit vane angle with respect to the flow of exhaustair.

The first and second exit vanes 154 provide control that is redundant tothe monocyclic pitch control, providing the control system withadditional control solutions to achieve a desired flight condition andproviding additional control power in the direction normal to the axesof rotation 24, 26 of the first and second rotors 14, 16.

I. Ballistic Parachute and Airbag

Battle damage, human error or component failure may cause the air module2 to cease operating within design parameters. The air module 2 or theground module 6 may include a ballistic parachute and airbag to protectthe ground module 6 and its occupants in the event of battle damage,human error or component failure.

The conventional ballistic parachute 156 is shown by FIG. 27. Theballistic parachute 156 includes a pneumatic parachute mortar 158mounted to the air module 2 or ground module 6. When the control systemdetects an aircraft condition outside of predetermine parameters, thecontrol system automatically fires the mortar 158, deploying theballistic parachute 156, lowering the ground module 6 and its occupantsand cargo to the ground 74.

The control system may constantly monitor motion and attitude of the airmodule 2, and directs a mortar pointing system to aim the mortar 158 ina direction that provides optimum deployment and inflation of theparachute 156. An example is directing the mortar 158 ahead of the airmodule 2 to provide a vector for the parachute 156 that will accommodateaircraft forward motion and prevent the parachute 156 from openingbehind the aircraft. The parachute 156 may be deployed by a steerablerocket to achieve the same end.

It is anticipated that the ballistic parachute 156 will reduce thevelocity of the air module 2 and ground module 6 combination to 12 feetper second. It is further anticipated that the speed of descent isfurther reduced to 6 feet per second by air bag 160. The long-travel,energy-absorbing landing gear 162 of the ground module 6 can absorb theremaining impact, protecting the occupants of the ground module 6.

As shown by FIG. 26, the airbag 160 is located on the bottom side 164 ofground module 6. Operation of the airbag 160 is conventional and theairbag 160 is deployed either before or during impact between the groundmodule 6 and the ground 74, as detected by accelerometers.

J. Air Module Control System

The control system 166 of the unmanned air module 2 is illustrated byFIGS. 29 through 31. From FIG. 29, the control system 166 includes amicroprocessor 168 operably connected to a computer memory 170. A powersupply 172 powers the control system 166. A control interface, which maybe a port 174, a radio transceiver 176, or both, allows communicationwith and programming of the control system 166.

The control system 166 includes a variety of sensors 178 that areoperably connected to the microprocessor. The sensors 178 include flightcondition sensors 180, such as attitude, airspeed, temperature,altitude, and rate sensors measuring changes to the measured flightconditions. Control surface position sensors 180 detect the position ofthe various flight controls, such as collective and cyclic pitch of eachrotor 14, 16, rotor tilt axis 20 location, rotor tilt for each rotor,wing extension deployment, active CG control position, vectored thrustorientation, and any other control information that is determined to beuseful. The engine parameter sensors 182 inform the microprocessor ofmatters relating to power, such as fuel reserves and consumption, enginepower, temperature of key components, throttle position, vibration andadditional engine power available. Navigation sensors 184 inform themicroprocessor of the location of the air module 2 in space and includesensors such as global positioning system receivers and terrain andobstacle detecting sensors such as RADAR and LIDAR transmitters andreceivers.

The microprocessor 168 is configured to actuate several effectors 186 tooperate the flight controls of the air module 2, including cyclic andcollective pitch effectors for each rotor 14, 16, engine throttlecontrol, effectors to change the location of the axis of rotor tilt 20,effectors to tilt the rotors 14, 16, active CG control effectors,effectors to deploy and retract wing extensions 56, 60, effectors todeploy a ballistic parachute 156, and engine 90 exhaust vectoringeffectors.

The microprocessor 168 is programmed to receive commands through thecontrol interfaces 174, 176. The commands may include specification of amission plan, a specified landing zone and waypoints between a startinglocation of the air module 2 and the specified landing zone. Themicroprocessor 168 is configured to operate as a conventional autopilotto fly the air module 2 on the route specified by the mission plan, topass through the specified waypoints and to land at the specifiedlanding zone, all without human intervention.

The control system 166 may receive command while in flight through theradio transceiver 176 to change the mission plan, waypoints or landingzone. The radio transceiver may receive the commands from a humanoperator at a remote location or from the ground module 6 when the airmodule 2 and ground module 6 are detached. When the air module 2 andground module 6 are attached, the ground module 6 may communicate withthe control system 166 through port 174. A human occupant of the groundmodule 6 may command changes to the mission plan, waypoints or landingzone.

FIGS. 30 and 31 illustrate operation of the autopilot air module controlsystem 166. The control mixer is an open-loop system that determines theactuator commands for all control effectors 186 on the aircraft as astatic function of the primary flight control inputs and the controlmode is determined by airspeed and the current duct tilt. The fourprimary control inputs to the mixer are the lateral, longitudinal,thrust and yaw controls. The control effectors 186 include symmetric anddifferential duct tilt, symmetric and differential cyclic pitch,symmetric and differential collective pitch, engine throttle, and cruiseflight pitch stabilization using thrust vectoring of engine exhaust.Control mixing can sometimes be achieved using a mechanical system, butfor a fly-by-wire configuration the mixing can be programmed forimplementation by the microprocessor 168. The latter approach providesgreater flexibility and more readily accommodates modifications andupgrades. Control mixing achieves the control modes to control roll,pitch, yaw and thrust in all flight configuration 18, 32, 38 and duringtransition between configurations. In transition between the low speedtandem rotor configuration 18, the low speed side-by-side configuration32, and the high speed tilted-rotor configuration 38, the controls willbe blended smoothly between the modes.

The inner loop flight controls use a dynamic inversion scheme since thestability and control characteristics vary significantly in the variousconfigurations 18, 32, 38. The inversion model can be scheduled as afunction of the duct tilt, airspeed, and configuration parameters toprovide consistent and predictable response characteristics across theflight envelope and configuration space.

In hover, tandem rotor configuration 18, and side-by-side rotorconfiguration 32, the controller will achieve attitude command/attitudehold (ACAH) response type in roll and pitch, and rate command/headinghold (RCHH) response in yaw. In tilted-rotor configuration 38 the pitchand yaw axes will include turn compensation modes, and the roll mode caneither be a rate command or attitude command system. The thrust controlwill be open loop in the core inner loop flight controls.

The RPM governing systems on tilted-rotor aircraft are particularlychallenging since the RPM must be regulated in both helicopter andcruise flight modes. Typically blade-pitch governing systems are used ontilted-rotor aircraft as they are more effective in airplane mode wherethe rotor torque is sensitive to changes in airspeed. The control system166 included blade-pitch governing. The pilot's thrust or collectivecontrol is directly tied to the engine throttle. The control mixingdetermines collective pitch as a sum of the feed forward collectiveinput and a trimming signal from the RPM governor. The feed forwardinput comes from the pilots' thrust input and the differentialcollective input (tied to roll and yaw axes). The RPM governor trimsignal is based on proportional plus integral compensation on the rotorspeed error from the nominal.

When the air module 2 is piloted, either by a human occupant of theground module 6 or by a human operator at a remote location, the outerloop control laws will achieve a translation rate command response typein rotary wing flight, where the vehicle lateral and longitudinal speedare proportional to pilot stick input. In the thrust axis, the controlwill achieve vertical speed command/height hold. Such a control law canallow operation in degraded visual environments or high confinedenvironments with reasonably low pilot workload. Upon the pilotreleasing the controls, the system will revert to full autonomouscontrol. In piloted tilted-rotor configuration 38, the outer loopcontrols will feature airspeed and altitude hold modes that can also beprogrammed through the displays. The outer loop control laws can be tiedto a basic way point navigation system.

Unlike a conventional tilted-rotor aircraft, symmetric and differentialduct tilt of the air module 2 will be part of the inner loop primaryflight control for the pitch, roll and yaw axes. The use of cyclic pitchon the rotors will be used to twist the ducts differentially through aflexible torsion beam 86, 88 and will reduce the actuation requirementsfor duct tilt during conversion to tilted-rotor configuration 38. Astiff rotor system 14, 16 will be used, so significant hub 96 momentscan be achieved by cyclic pitch. If engines 90 are selected having highexhaust gas flow rates, the exhaust gas can be vectors to provideadditional control in pitch when the air module 2 is in the tilted-rotorconfiguration 38.

K. Alternate Rotor Configurations

FIGS. 32 through 34 illustrate alternate configurations that rotary wing4 may take. FIG. 32 illustrates a single ducted fan or single open rotor188 embodiment of the air module 2. A single rotor 14 is powered by thecentral unit 50. A propeller 190 mounted on a boom 192 reacts the torqueof the single rotor 188 to control yaw. The single rotor 188 embodimentis modular and the air module 2 and ground modules 6 may be operatedindependently; however, the air module 2 and the air module 2 and groundmodule 6 combination may fly in only one configuration as a rotary wingaircraft.

FIG. 33 illustrates a coaxial open rotor 194 embodiment of the airmodule 2. Two counter-rotating coaxial rotors 14, 16 are powered by thecentral unit 50. Because of the counter-rotating rotors 14, 16, thetorque reaction of each rotor cancels that of the other and no boom 192or propeller 190 is required. The coaxial open rotor 194 embodimentotherwise is similar to the single open rotor 188 embodiment of FIG. 32and may fly in only one configuration as a rotary wing aircraft.

In each of FIGS. 32 through 34, the air module 2 and ground module 6 aremodular and may be detached and each may operate independently of theother. The air module 2 may take off, fly and land independently fromthe ground module 6. Where the ground module 6 is a vehicle groundmodule 70, the vehicle ground module 70 may operate on the ground 74under its own power independent of the air module 2. The air module 2and ground module 6 may be joined selectably so that the air module 2supports the ground module 6 in flight and the ground module 6 supportsthe air module 2 when on the ground.

FIG. 34 illustrates an autogyro air module 196 embodiment. The engine 90in central unit 50 powers a vectored thruster 198, such as a propelleror ducted fan. The vectored thruster 198 is shown by FIG. 35 as a pusherpropeller on boom 200, but the vectored thruster 198 may be a tractorpropeller and may be mounted to ground module 6. The vectored thruster198 provides forward thrust to the air module 2 and ground module 6combination. Air moving from the underside of the spinning rotor disc tothe top side of the rotor disc causes the rotor 14 to keep rotating,generating lift and maintaining the air module 2 and ground module 6combination airborne.

Any of the embodiments may be equipped with a propeller or othervectored thruster 198 to provide forward thrust in addition to thrustfrom the open rotor 188 or the ducted fan 46, 48.

The autogyro air module 196 may be a ‘jump’ autogyro. For takeoff, therotor 14 is connected to the engine 90 and rotor 14 is turned by theengine, storing kinetic energy in the rotor 14. The rotor 14 isdisconnected from the engine 90, the collective pitch of the rotorblades 94 is increased, causing the rotor 14 to generate lift, and theengine 90 is connected to the vectored thruster 198. The air module 2rises vertically and is driven forward by the vectored thruster 198.When the aircraft reaches an adequate forward speed, the air movingthrough the rotor 14 is adequate to maintain the rotation of the rotorblade 94 and to maintain flight. The autogyro air module 196 and groundmodule 6 are modular and operate in the same fashion as the ducted fanair 46, 48 module and the open rotor air module 188.

Air module 2 may be in any other configuration known in the rotary wing4 aircraft art, including a twin rotor aircraft having intermeshingrotors and a tandem rotor aircraft that is not capable of transitioningto the side-by-side rotor configuration 32 or the tilted-rotorconfiguration 38. The air module 2 may have two rotors in theside-by-side rotor configuration 32 that are not capable of moving tothe tandem rotor configuration 18 or the tilted-rotor configuration 38.The air module 2 may be an aircraft that is capable of flying in theside-by-side rotor configuration 32 and the tilted-rotor configuration38, but that is not capable of flying in the tandem rotor configuration32.

FIG. 35 illustrates a rotor mast 202 of the autogyro air module 196. Therotor mast 202 incorporates both an extendable mast 204 for groundobstacle avoidance and a tiltable rotor mast for active center ofgravity (CG) control. Rotor 14 is attached to autogyro rotor hub 206.Rotor 14 spins about center of rotation 24 of autogyro rotor hub 206.Mast 202 transmits lifting forces from the rotor hub 206 to the centralunit 50 of air module 2. Mast 202 comprises a first mast portion 208 anda second mast portion 210. First and second mast portions 208, 210 arein a telescoping relationship and may be keyed or splined to avoidrotation of the first and second mast portions 208, 210 with respect toeach other. Alternatively, the first mast portion 208 may turn with therotor 14 with respect to second mast portion 210 and may define therotor bearing allowing the rotor 14 to turn. Rotor extension screw jack212 operates on rotor extension screw 214, which is attached to firstmast portion 208. The position of the rotor extension screw determinesthe extended length of rotor mast 202.

Alternatively, rotor extension screw jack 212 and rotor extension screw214 may be dispensed with and the extension of the autogyro rotor mastdetermined by the lift generated by the rotor 14. When the rotor 14 isspun by the engine 90 for takeoff, the lift generated by the spinningrotor 14 extends the rotor mast 202. When the aircraft lands and therotor 14 slows, the rotor 14 loses lift and the mast 202 moves from theextended to the retracted position.

FIG. 35 also shows active CG control for the autogyro air module 2through tilting of rotor mast 202. Rotor mast 202 is attached to centralunit 50 through hinge 216. The nature of hinge 216 depends on the axesof active CG control. For one axis of CG control, hinge 216 can be anaxle and bearings supporting the axle. For two axis CG control, hinge216 can be a ball joint. For two axis CG control, a second rotor tiltscrew jack 218 is utilized for control in the second axis. Rotor tiltscrew jack 218 tilts rotor mast 202 about hinge 216, and hencedetermines the location and orientation of rotor lift with respect tothe CG of the aircraft. The rotor tilt screw jack 218 is the CG actuatorattached to the CG control system of FIG. 20.

FIG. 36 illustrates a rotor tilt active CG system for a open rotor airmodule 2 that files as a helicopter and as illustrated by FIGS. 9through 11, 32 and 33. Screw jack 220 determines the tilt of rotor mast202. The rotor drive shaft 222, contained within rotor mast 202,transfers power to rotor 14 through a flexible coupling 224. The screwjack 220 is the CG actuator shown by FIG. 21 to move the center of liftof the air module 2 with respect to the center of gravity.

FIGS. 37 and 38 illustrate an extendable rotor mast 202 for an openrotor 188 air module 2 that flies as a helicopter and as illustrated byFIGS. 9 through 11, 32 and 33. The extendable rotor mast 202 allows therotor 14 to have a lower profile for ground transportation of the airmodule 2, but allows the rotor 14 to have a higher configuration forsafe ground operations when the rotor 14 is turning.

FIG. 37 illustrates the extendable rotor mast 202 in the contracted(lower) position. Drive shaft 222 is turned by engine. Drive shaft 222is splined to rotor shaft 226, so that rotor shaft 226 may slidably movein a longitudinal direction with respect to drive shaft 222 and so thatdrive shaft 222 transmits rotational power to rotor shaft 226. Rotorshaft 226 turns rotor 14. Rotor mast 202 includes a first rotor mastportion 228 and a second rotor mast portion 230. First rotor mastportion 228 is attached to hub 96 and second rotor mast portion 230 isattached to central unit 50. First and second rotor mast portions 228,230 are splined or keyed one to the other and do not rotate with rotor14. First and second rotor mast portions 228, 230 maintain thestationary portion of swashplate 98 within hub 96 in a stable position.First and second rotor mast portions 228, 230 are movable with respectto each other by rotor extension screw jack 232 and screw 234.

FIG. 38 shows the extended position of the extendable rotor mast 202 ofFIG. 38. Splined driveshaft 222 and rotor shaft 226 transmit power toturn rotor 14 while first and second mast portions 228, 230 do notrotate and maintain swashplate in hub 96 in a stable, stationarycondition.

Rotor extension screw jack 232 and screw 234 may be dispensed with andlift generated by the rotor 14 may be used to extend extendable rotormast 202. Loss of lift from the slowing rotor 14 after landing mayautomatically retract extended rotor mast 202.

In this document, the term “screw jack” refers to screw jacks and to anyother conventional apparatus to transmit linear motion, including ahydraulic cylinder and a rack and pinion.

The open rotor air modules of FIGS. 9 through 11, 32 and 33 may beconfigured to have a rotor 14 with extendable blades 236, illustrated byFIGS. 39 through 42. FIG. 39 shows the extendable blade 236 in theretracted position for ease of ground travel. FIG. 40 shows theextendable blade 236 in the extended position. The extendable blades 236are telescoping, as illustrated by FIGS. 40, 41 and 42.

FIGS. 41 and 42 are a cutaway plan views showing the telescoped blades236 in the retracted and the extended positions. The telescoping blades236 are illustrated have three sections, 236 a, b and c, thoughextendable blades 236 with two sections or with more than three sectionsare contemplated by the invention. Blade extension screw jacks 238 andblade extension screws 240 move the blades 236 between the extended andretracted positions.

What is claimed is:
 1. An air vehicle, the air vehicle comprising: a. anair module; b. at least one rotary wing operably attached to said airmodule; c. said air module is configured to be selectably attached to aground module, said at least one rotary wing being configured to supportsaid ground module and said air module in a flight when said groundmodule and said air module are attached, said rotary wing beingconfigured to support said air module in said flight when said groundmodule and said air module are not attached; d. a center of gravityeffector, said center of gravity effector being configured to locate acenter of gravity of said ground module with respect to a center of liftof said air module when said air module is attached to said groundmodule; e. a sensor, said sensor being configured to detect a change inan attitude of said air module or said ground module, a microprocessoroperably connected to said sensor, said microprocessor being configuredto send a center of gravity correction signal in response to a change inattitude detected by said sensor; f. said center of gravity effectorbeing a dynamic center of gravity effector that is movable in onedimension, said dynamic center of gravity effector being configured toreceive said center of gravity correction signal from saidmicroprocessor, said air module having a center of lift when said airmodule is in flight, said ground module and said air module having acenter of gravity when said ground module and said air module are inflight, said dynamic center of gravity effector being configured tochange a relative location of said ground module with respect to saidair module in said one dimension, whereby said dynamic center of gravityeffecter changes a relative location of said center of gravity and saidcenter of lift.
 2. The air vehicle of claim 1, further comprising: acenter of lift effector, said center of lift effector being configuredto receive said center of gravity correction signal from saidmicroprocessor, said center of lift effector being configured to changesaid center of lift of said air module, whereby said center of lifteffecter changes a relative location of said center of gravity and saidcenter of lift.
 3. The air vehicle of claim 1 wherein said at least onerotary wing is tiltable about an axis of rotor tilt to a tilted positionand wherein said one dimension is normal to said axis of rotor tilt,said dynamic center of gravity effector being configured to change arelative location of said ground module with respect to said air modulein said one dimension generally normal to said axis of rotor tilt whensaid air and ground modules are attached.
 4. The air vehicle of claim 3wherein said center of gravity effector is configured for passiverelative movement of said air module and said ground module in a seconddimension when said air module and said ground module are attached, saidsecond dimension being generally parallel to said axis of rotor tilt,whereby when said ground module is attached to said air module saidcenter of gravity effector is configured to allow relative movement ofsaid air and ground modules passively in said second dimension withoutintervention by said microprocessor and without reference to said centerof gravity correction signal.
 5. The air vehicle of claim 4 wherein saidpassive relative movement in said second dimension is damped to preventoscillation between the ground and air modules when the ground and airmodules are attached.
 6. The air vehicle of claim 1 wherein said centerof gravity correction signal is configured to command said center ofgravity effector to move said ground module vertically with respect tosaid air module, said center of gravity effector being configured toactively change a relative location of said ground module with respectto said air module in said vertical dimension when said ground and airmodules are attached.
 7. The air vehicle of claim 3 wherein said dynamiccenter of gravity effector is configured to change a relative locationof said ground module with respect to said air module in a seconddimension when said ground and air modules are attached, said seconddimension being generally parallel to said axis of rotor tilt, wherebysaid dynamic center of gravity effecter may change a relative locationof said center of gravity and said center of lift in said seconddimension.
 8. The air vehicle of claim 7 wherein said center of gravitycorrection signal is configured to command said center of gravityeffector to move said ground module in a vertical dimension with respectto said air module, said center of gravity effector being configured toactively change a relative location of said ground module with respectto said air module in said vertical dimension when said ground and airmodules are attached.
 9. The air vehicle of claim 1 wherein said dynamiccenter of gravity effector comprises a cross slide, said cross slideallowing relative motion in said one dimension between said air moduleand said ground module under a control of said center of gravitycorrection signal when said air module and said ground module areattached.
 10. The air vehicle of claim 1 wherein said dynamic center ofgravity effector comprises a crank, said crank allowing relative motionin said one dimension between said air module and said ground moduleunder a control of said center of gravity correction signal when saidair and ground modules are attached.
 11. The air vehicle of claim 1wherein said dynamic center of gravity effector comprises a pinned link,said pinned link allowing relative motion between said air module andsaid ground module under a control of said center of gravity correctionsignal when said air and ground modules are attached.
 12. An airvehicle, the air vehicle comprising: a. an air module; b. at least onerotary wing operably attached to said air module; c. said air module isconfigured to be selectably attached to a ground module, said at leastone rotary wing being configured to support said ground module and saidair module in a flight when said ground module and said air module areattached, said rotary wing being configured to support said air modulein said flight when said ground module and said air module are notattached; d. a center of gravity effector, said center of gravityeffector being configured to locate a center of gravity of said groundmodule with respect to a center of lift of said air module when said airmodule is attached to said ground module wherein said center of gravityeffector is configured for passive relative movement of said air moduleand said ground module when said air module and said ground module areattached, whereby said center of gravity effector is configured to allowrelative movement of said air and ground modules automatically inresponse to a change in said center of gravity without intervention by acontrol system.
 13. The personal-air vehicle of claim 12, furthercomprising: a. a sensor, said sensor being configured to detect a changein an attitude of said air module or said ground module, amicroprocessor operably connected to said sensor, said microprocessorbeing configured to send a center of gravity correction signal inresponse to a change in attitude detected by said sensor; b. a center oflift effector, said center of lift effector being configured to receivesaid center of gravity correction signal from said microprocessor, saidair module having a center of lift when said air module is in flight,said ground module and said air module having a center of gravity whensaid ground module and said air module are in flight, said center oflift effector being configured to change a center of lift of said airmodule, whereby said center of lift effecter changes a relative locationof said center of gravity and said center of lift.
 14. The air vehicleof claim 12 wherein said center of gravity effector comprises a linkthat is free to move in two dimensions, said link having two ball jointsthat connect said link to said air and ground modules when said air andground modules are attached.
 15. The air vehicle of claim 12 whereinsaid center of gravity effector comprises a strap, said strap allowingmovement of said ground module with respect to said air module in twodimension when said air and ground modules are attached.
 16. The airvehicle of claim 13 wherein said at least one rotary wing is tiltableabout an axis of rotor tilt to a tilted position and wherein said centerof gravity effector is configured for passive relative movement of saidair module and said ground module when said air module and said groundmodule are attached in at least one dimension, said one dimension beingnormal to said axis of rotor tilt.
 17. The air vehicle of claim 13wherein said center of gravity correction signal is configured tocommand said center of gravity effector to move said ground modulevertically with respect to said air module, said center of gravityeffector being configured to actively change a relative location of saidground module with respect to said air module in said vertical dimensionwhen said ground and air modules are attached.
 18. The air vehicle ofclaim 13 wherein said center of lift effector is configured to move saidrotary wing with respect to said air module and to thereby change therelative locations of the said center of lift and said center ofgravity.